The PI recently developed a new methodology for the study of human cells implanted in the rat (1, 2). Basically the method involves encapsulation of cells into the lumen of XM-50 hollow fibers (Romicon Corp.). These fibers are constructed in such a way that molecules greater than 50,000 daltons (Plus/minus 5%) are excluded from either leaving or entering the capsule lumen. Therefore, allogeneic cells in the fiber are not subject to influence of IgG molecules (150,000 daltons) from the host. Thus the transplanted tissue is, in theory, maintained in an immunologically privileged configuration. The framework for this proposal stems from our preliminary data (Section C) which shown that human prostate cells prepared from both BPH and carcinoma specimens retain morphological identify upon encapsulation in hollow fibers and implantation into the rat 1-3 weeks post implantation. Furthermore, our ability to detect human prostatic antigen (PA) in the blood of the recipient argues for maintenence of functional cells in this configuration. The specific aims of this proposal are: 1). to develop a simple, reliable model for the study of human prostatic cell function in the rat, and 2). to test the hollow fiber model for its usefulness in evaluating the hormonal responsiveness/chemosensitivity of prostatic carcinoma cells from individual patients. To meet these specific aims, a series of nine protocols are detailed. Measurement of PA in the serum of recipients will constitute an important response criterion. Another will be the chemical assay of capsule DNA contents before and after implantation to assess various treatment effects on cell turnover. These experiments will, if successful, be instrumental in development of a new model system for heterotransplantation of human prostatic cells in the rat. As such, the experiments appear compatible with stated goal #2 of the NPCP, viz. "to improve and standardize available experimental models and to develop new ones for investigations into the prevention, detection and treatment of prostatic cancer."